It depends on how old my child is and what type of person he or she is, I suppose.
I plan on being as truthful and age appropriate as I can. But, since I am not a parent yet, I realize that many of my plans will probably be sacrificed once the reality of raising kids comes home to roost.
Had to do this one with some fish that got flushed. Sorta cheated on this one though because my son watched Finding Nemo and immediately told me that they were returned back to the ocean. As for other animals though (like in the wild), I've been straight forward with him on it. Tried not to get too graphic about what happens to the body after they die in the woods or where ever, but he got the point.
You call it bribery, I call it "random positive feedback".
I thought about this some more and remembered what actually happened after both grandfathers and several pets had died -- "all life ends in death but your friends and relatives remember you just like you remember your relatives and friends that die. Pets and people are wonderful examples of other lives that we get to share so treat everyone like you would like to be treated and you will have lots of friends that remember you when you are gone."